A chemotactic synthetic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) an analog of bacterial products is injected into the rabbit cornea, skin and vitreous to induce a reaction resembling the "Arthus phenomenon." Injection of FMLP induces edema and granulocytic infiltration in the cornea, conjunctiva and skin. Perivasculitis is also observed in the conjunctiva and skin. These histologic changes are compared with the inflammation induced by complement component C5a or by OVA in specifically immunized rabbits. The time course of the appearance, peak time, and subsiding inflammatory reactions induced by FMLP, C5a and rechallenge with antigen (OVA) are inhibited by topical application and subconjunctival injection of dexamethasone, quinacrine, analog of arachidonic acid (ETYA) and indomethacin, agents that inhibit different sites of chemotaxis of polymorphonuclear leukocytes (PMN's). We are determining whether the inflammation induced by FMLP would be inhibited by carbobenzoxy-phe-Met (Z-phe-Met) a competitive inhibitor of FMLP for the PMN's receptor in vitro.